Telegraphic code.



lPa'fented june 25, lsol.

c. G. BURKE. yTau-:armani: cons.

(Applclton hd Mar. 29, 1900.)

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UNITED STATES PATENT OFFICE..

CHARLES G. BURKE, OF BROOKLYN, NEW YORK, ASSIGNOR OF ONE-HALE TO JOHN Q.A. WHITTEMORE, OE BOSTON, MASSACHUSETTS.

TELEGRAPHIC CODE,

SPECIFICATION forming part of Letters Patent No. 676,936, dated June 25,1901. Application tiled March 29, 1900. Serial No. 10,601. (No model.)

To cir/ZZ whom, it nty concern:

Be it known that I, CHARLES G. BURKE, a citizen of the United States,residing at the borough of Brooklyn, in the city of New York,

county of Kings, and State of New York, have invented certain new anduseful Improvements in Telegraphic Codes, of which the following is aspecification, reference being had to the drawings accompanying andforming Io a part of the same.l

This invention refers to that class or system of telegraphywhereintelegraphic signals are sent over a telegraph-line and made to act on areceiving instrument so as to produce a record indicating the deviationsof a stylus or siphon in opposite directions from a zero point or line.Heretofore it has been usual in operatinginstruments of this form todesignate the deviations from zero in one 2o direction as dots and intheother direction as dashes and by combinations of these so-formed dotsand dashes to indicate the letters 'of the alphabet, numerals, and otherdesired significations. As all signals representing letters, 85e., underthis arrangement have to be composed of these dots and dashes usedsingly, in multiple, or in combinations, the forming of a `code for thetwenty-six letters of the alphabet, the numerals, duc., necessitates theemployment of deviations in opposite directions for all of the lettersexcept four and all of the numerals except one. As a consequenceSiphon-recorder signals as now made present a zigzag appearance, and theSiphon in producing the record .has to be moved over a considerablespace while passing to and from the extreme limit of deviation in onedirection to the extreme of deviation in the opposite direction in allsuch cross 1o combinations. These long movements of the siphon areobjectionable because of the ex-v tra time which is involved. Besides,the record becomes more or less illegible and difficult to decipherandnecessitates skill for its ,4 5 correct interpretation. In myimprovement I avail myself ofthe capability of receiving instruments ofthe kind described to produce a recognizable dierence in extent ofdeviation in either direction, as well as their ability 5o to indicateadi'erence in length between succeeding deviations in either direction.Y By this means I command several unit elemental signals, whereas buttwo are available under present methods. On account of this increasednumber of elemental units I am enabled to form a code for the letters ofthe alphabet, numerals, and other desired significations wherein allcomplete signals may be on one side of thezero point or line, thusavoiding lthe necessity of the siphon crossing 6o zero while formingcomplete signals or any complete combination of signals. Such a recordis clear and uniform in character, easily deciphered, and the signalsmade more rapidlyand by fewer electric impulses. In practiceI find thateight of these unit-signals give the best general. results, and in thisspecification I will confine myself to describing how I produce theseeight units and how theyare employed in telegraphy, it being under 7ostood that more than eight or less than that number may be produced andused in the same Way. As a basis I select four signals distinguishablefrom each other by a difterence in their respective lengths-that is tosay, by the evidence of the difference in time between successiveimpulses. For convenience I designate these four elemental unitsignalsas signals Nos. 1, 2, 3, and t. Unitsignal No. 1 is produced by sendingan elec- 8c tric impulse of a given duration and polarity over the linefor the purpose of causing the Siphon to be moved from zero to a certaineX- tent in a direction depending upon the polarity of the impulse.Thereby I indicate the beginning of the signal. After the lapse of oneunit of time a second impulse of the same duration and like polarity issent, and this completes signal No. l. Signal No.2 is produced in thesame way, two units of time be- 9o ing permitted to intervene, however,between the impulses. For signals Nos. 3 and 4 three and four units oftime, respectively, are made to intervene between their respectiveinitial and iinishing impulses. In addition to these four unit-signalelements diering in length I also employ four other signalsdistinguishable from them by the effects produced in the recordinginstrument and in the record by a prolongation of the duration of theimpulses Ioo by which theI beginning of signals is indicated. Forconvenience these additional sighals may be designated as signals plus1, plus4 2, plus 3, and 'plus 4. To produce plus-sigvpleted by oneimpulse of .briefer contact. The

effect of this increase in the durationof the initial impulse is tocause a wider deviation from zero than in the case of signal No. 1, so

that although signal plus 1 and signal No. 1 g

agree in length of time elapsing between the initial and finishingimpulses they will be distinguishable from -each other` by adierence inthe extent of deviation of their initial impulses from the zero-line.Signals plus 2, 3, and 4 differ from signals Nos. 2, 3, and 4 by only alike increase in the extent of deviation of theinitial impulse. Inpractice I find that an increase of' one-third the ordinary period ofthe electric contact is quite sufficient to make these differencesunmistakable. It is obvious that when these signals follow each other,as would be the case in all combinations of two or more of them, theimpulse which is required to define the termination of the time unit orunits of the first signal will alsor serve, to indicate the beginningofthe time unit or units of the next succeeding signal, and so on to thelast signal in the combination, which of course requires a inal impulse.In practice, therefore, it may be said that the transmission andrecording of each symbol or signal, except thev last, of a combinationof two or more requires but one electric impulse. For example, totransmita combination of signals corresponding to the figures 2314, Isend an initial positive impulse over the line, then after two unitsoftime a second impulse, thenafter three units of time a third impulse,again after one unit of time a fourth impulse, and

then after four units oftime thev fifth or finalV impulse. Asuitably-constructed receiving y apparatus will1 in response to suchsignals trace marks on the paper or tape, separated from each other bylines of two, three, one, and four units of length, respectively.

While in my system I 4discard entirely the use of the usual signals forindicating letters of the alphabet and numerals, I may, and in practiceIdo, assign to the more simple sign'als or combinationsthe letters ofthe alphabet, numerals, short words in frequent use, punctuation-marks,andthe like, so that my system may be operated entirely independently ofany ofthe codes now in use for the transmission of all kinds ofmessages, and

always with the advantage of increased speed, accuracy, and simplicity.

In transmitting messages each complete combination of signals used forindicating different number or figure rcombinations is separated fromadjacent combi-nationsby space-marks longer than thelongest symbol Fig.4 shows the record ofl groups of signals arranged 'to spell out givenwords.

In Fig. 1 the zero-line is designated by A, the marks made by the stylusor pen of the recorder when actuated by a primary impulse by B, andthose made by an impulse of increased duration by C. The signal for thenumeral l will therefore be indicated by 'two of the elemental marks B,separated by one unit of space or time, that for. 2 by two of suchmarks, separated by two space-units, and so on, whilethenumerals l, 2,3, and 4 will be similarly indicated by the plus-marks C, which havevgreater de- Viation from the line A. By-selected combinations of thesesignals, as above explained, I may indicate the letters of the alphabet,the

signals used, preferably, for thi-s purpose being indicated in Figs. 2and 3.

As I have stated before, the impulses may be on the opposite side of thezero-line from that illustrated.

.The transmission of signals by this means is Very much simplified, andthe best condi- 'tions for rapid Working of the line are secured.

1. A telegraphiccode in which the signal elements are distinguished fromone another by a difference in length and by their relajtion to a givenzero posit-ion, andV in which each group or combination of elementswhich vrepresents a given letter or character is made u pv of elementshaving the. same relation.v to such zero position, as set forth.,

2. A telegraphic code in which the signal elements are distinguishedfrom oneanother by a dierence in length and form, andv by theirrelationto a given zero position, and inwhich each group or combinationof elements v which represents-a given letter or character is made up ofelements which have the same relation to" such zero position, as-setlforth.

3. A telegraphic code composed of a pl u.

rality of groups off-signal elements, each group representing a givenletter or character, and characterized by the relation of its componentelements to a given zero position, the several elements of each group.b'eing'disti-nguished bya difference in form corresponding to thestrength of the current impulses` producing them, as set forth.

' vCHARLES G. BURKE.

. Witnesses:

M. Lawson DYER, JOHN C; Knien.

IOO

